https://mediatum.ub.tum.de/doc/1218638/file.pdf

First report on chicken genes and chromosomes 2000

The coupling of bone resorption and formation suggests that autocrine and paracrine factors are produced and released within the local bone environment. Since osteoblasts secrete latent transforming growth factor beta (TGF-beta), and osteoclasts can activate this latent complex, one candidate paracrine coupling factor is TGF-beta. To examine whether TGF-beta is also a potential osteoclast-derived autocrine and paracrine factor, highly purified avian osteoclasts were examined for synthesis of TGF-beta and the mechanism by which osteoclasts activate the latent TGF-beta complex was investigated. TGF-beta protein production was measured within 4 h of culture in osteoclast-conditioned media using growth factor inhibition of CCL-64 cells and verified by blocking effects with anti-TGF-beta antibodies. Synthesis of TGF-beta was confirmed by northern blotting and metabolic labeling. Northern blots of total RNA revealed that osteoclasts expressed the mRNA for TGF-beta 2, beta 3, and beta 4. Biosynthetic studies suggest that TGF-beta 2 was the principle form secreted in culture. Nearly all the TGF-beta that was secreted had been activated by the osteoclasts. When presented with exogenous latent TGF-beta, osteoclasts activated latent TGF-beta from a variety of sources. Furthermore, osteoclast-conditioned media retained the ability to activate latent TGF-beta during cell-free incubations at 37 degrees C. Osteoclast-mediated activation was inhibited by proteinase inhibitors, weak base treatment of the cells, or disruption of the cytoskeletal network. These data suggest that osteoclasts may secrete proteinases into the extracellular milieu to activate latent TGF-beta and that TGF-beta may be an autocrine factor involved in regulating osteoclast activity.

Osteoclast synthesis and secretion and activation of latent transforming growth factor β

Structural and functional characterization of the mouse hepatocyte growth factor gene promoter.

https://www.zora.uzh.ch/id/eprint/50/1/Sch%C3%A4ffer2003MaV.pdf

Oxygen-regulated Expression of TGF-β3, a Growth Factor Involved in Trophoblast Differentiation

Our goal was to determine whether transforming growth factor beta (TGFbeta) isoforms were involved in the process of sperm survivability in the sperm-storage tubules (SST) in the utero-vaginal junction (UVJ) of hen oviduct. The birds were artificially inseminated. The mRNA expressions of three types of TGFbeta isoforms (TGFbeta2, TGFbeta3, and TGFbeta4) and three types of receptors (TbetaR1, TbetaR2, and TbetaR3) were examined in the presence or in the absence of resident sperm in SST by semi-quantitative reverse transcriptase-PCR. The mRNA expression of TGFbetas and TbetaRs in sperm was also examined. Immunocytochemistry and western blot were performed for TbetaR2 to confirm its localization in UVJ. The sperm were observed at least 10 days after insemination by histology. The mRNA expressions of TGFbetas and TbetaRs were significantly increased in UVJ in the presence of resident sperm in SST. The mRNA expressions of TGFbetas and TbetaRs were also observed in sperm. Immunohistochemistry revealed that TbetaR2 were located in lymphocytes in UVJ and SST cells. The presence of TbetaR2 in UVJ was also confirmed by western blot. These results suggest that enhanced expressions of TGFbetas and TbetaRs in UVJ may protect sperm in SST, probably by suppressing anti-sperm immunoreactions.

/pdf/expression-of-transforming-growth-factor-b-isoforms-and-2zc4ar6phe.pdf

Expression of transforming growth factor-β isoforms and their receptors in utero-vaginal junction of hen oviduct in presence or absence of resident sperm with reference to sperm storage

The promoter regions of the three mammalian transforming growth factor-beta genes (TGF-beta s 1, 2, and 3) have been recently cloned and characterized. The sequences show little similarity, suggesting different mechanisms of transcriptional control of these genes. To study differences in transcriptional regulation of mammalian and avian TGF-beta, we have cloned and sequenced the 5'-flanking region of chicken TGF-beta 3. Characterization of this region showed a TATA box and cAMP-responsive element (CRE) and AP-2 binding site consensus sequences starting at 12 and 28 base pairs, respectively, upstream from the TATA box. Moreover, four additional AP-2-like sites, 10 binding sites for the transcription factor Sp1, as well as two AP-1-like sites were also identified. Except for 32 base pairs of identity centered around the TATA box and CRE site and four other relatively small regions of identity, the chicken TGF-beta 3 promoter was found to be structurally very different from the human TGF-beta 3 promoter. Pro...

/pdf/identification-and-characterization-of-the-chicken-45nbhqltxz.pdf

J Cubert

Papers

Identification and characterization of the chicken transforming growth factor-beta 3 promoter.